Socket for incandescent lamps



(N0 Modem T. L. PPARR, Jr. SOCKET FOR INOANDESGENT LAMPS.

I No. 512,448 Patentd Jan. 9, 1894. r

II llll llllilllu Ill lllllizi i [LEW UNITED STATES PATENT OFFICE.

THOMAS L. PFARR, JR, OF PITTSBURG, PENNSYLVANIA.

S OCKET FOR INCANDESCENT LAMPS.

SPECIFICATION forming part of Letters Patent No. 512,448, dated January9, 1894. Application filed February 13, 1893. Serial No. 462,094. (Nomodel.)

T at whom at may concern.-

. tion with incandescent lamps.

Heretofore where incandescent lamps have been employed for lightingpurposes, and it was desired to transmit light or power from one of suchlamps, permanently secured to a bracket, to a distant point, as forinstance to i a drop light or toa motor for operating a fan or othercontrivance, it was necessary to remove the bulb from the lamp andinsert a plug in the lamp socket with conductors at tached thereto ofsufficient length to carry the electricity to the point of use. Such aconnection was of necessity made at the expense of the light in the lampfrom which the connection was made to the drop-light or motor. It wasimpossible, therefore, to trans unit the electricity from the fixed lampto a distant point to supply another lamp or a motor, and yet have thebenefitof the light in the fixed lamp.

The object of my-invention is to provide a socket and plug by. means ofwhich the electricity may be transmitted from one fixed lamp to adistant point to be used for lighting or other purposes withoutdispensing withthe light afforded by said fixed lamp unless so desired.I

To these ends my invention comprises, generally stated, a bulb holderfor an incandescent lamp having terminals therein adapted to connectwith the supply wires, and a loop containing a switch leading from saidterminals to the lamp of a removable branch fitting or plug havingcontact points and adapted to enter through the side of the bulb holderand contact with the terminals beyond the loop and switch in the bulbholder, so providing for carrying the current from the bulb holder to adrop light, motor, or like device, without interfering with the burningof the lamp supported in the bulb holder.

It also consists in certain other improvements in connection with thedevice as will be hereinafter described and claimed.

' To enable others skilled in the art to make and use my invention, Iwill describe the same more fully, referring to the accompanyingdrawings, in which Figure l is a view illustrating-the electro- I lierwith branches therefrom to run a motor, or for a drop-light. Fig. 2 is across section illustrating the connection between the bulb holder andthe branch fitting or plug. Figs. 3 and 4 are sectional views of anotherform of the device, and Figs. 5 and 6 are views of the bulb holdershowing the movable collar.

Like letters of reference indicate like parts in each View.

As above indicated, the object ofthe invention is to provide for thebranch fittings to be applied to the bulb holder, and in theaccompanying drawings the bulb holder is represented at at having thebulb or lamp b, two such bulb holders and lamps being illustrated inFig. 1, while a branch fitting c is connected to each such bulb holder,one extending to the motor operating a fan d, and the other extending tothe drop-light e upon a table 6, the connections from the bulb holder tothe drop-light or fan being made by means of the usual covered wires. Inthe ordinary construction of the bulb holder the current is carried tothe same through suitable wires, the one Wire being connected to thebinding screw f and thence to the spring fingers f retaining the bulb,while the other is connected to the contact spring of the bulb holderthrough the binding screw g, the current from the two wires being thuscarried to the carbon filament within the lamp. For the purpose ofmaking connection with these two binding screws or contact surfacesfg Iconnect to them the contact pieces f 2 g which extend toward one side ofthe bulb case, the form thereof being preferably that of spring lips soas to engage with the contact points of the branch fitting c. Thecontact pieces f 2 g are arranged oppoite the openings h it formed inthe side of the shell or case a of the bulb ,holder, these openingsproviding for the entrance of the branch fitting which has the hollowinsulated tubes or like projecting portions 0 within which are thecontact points 7c 70, which also preferably have the form of springlips, as shown, and which, when the tubes 0' 0 pass through the openings72. it, provide for the bringing of the contact points k 70' intoengagement with the contact pieces f 2 The connection from thebindingscrews fg to the contact pieces is made in any suitable way, andis made above the key i which turns on or cuts the current 01f thelampheld within the bulb holder, so that the current is taken from theconductorsin such position that it does not interfere with the turningon or turning olt' of the lamp held in the bulb holder, adding simplyanother short circuit through the main conductors to which the wiresfeeding the current to the bulb holder are connected. U The contactpieces 7a k are connected to suitable conductors within the plug orbranch-fitting c, the wires to carry the current from the branch fittingbeing c011- neeted to suitable binding screws therein and leading thenceto the drop-light which contains a like bulb holder, so that the lightis carried from the main bulb holder on the electrolier to thedrop-light, and the current can be arranged by the turning of theordinary switches within the bulb holders so as to feed both the lamp onthe main bulb holder on the electrolier and that on the drop light. Inthe same way the current is carried to the motor, or other likeconnections with which it is to be utilized.

The construction of the branch fitting can, of course, be variedaccording to the bulb holder with which it is to be connected, theconstruction shown in Fig. 2 being that usually employed with theordinary Edison lamp in which the binding screws for the wires arelocated some distance from each other, and the key or switch betweenthem, and therefore two openings in the side of the shell a arerequired, and the contact pieces of the branch fitting pass through thesame to make contact with the conductors of the bulbholder. In such casethe branch fitting consists of a small case or box 0 of suitable shape,having the wires leading from the contact points 7.; k to suitablebinding screws k 71: therein and suitable insulating material beingemployed so as to prevent the current from passing between the saidbinding screws, the wire cords 70 70 leading from said binding screws,this being a very simple construction. Another example of the devicewhen applied to another form of bulb holder is shown in Figs. 3 and 4:,the binding screws Z Z to which the wires are connected being seated ina suitable insulating block, and extending through the same andconnected to suitable contact springs with which the bulb engages. Insuch case I can eniploya single tube, or like projecting piece from thebranch fitting, which will contain both of the contact fingers orpoints, the same being insulated from each other by a suitablelongitudinal strip within the tube, and the case of the bulb holderhaving only one opening in the side thereof, and the tube being passedinto the bulb holder so that its contact points engage with the bindingscrews or like surfaces. For such purpose, it may be necessary to changesomewhat the form of the device by drawing the binding screw to one sideso as to permit the entrance of the tube. This is clearly shown in Fig.4., in which an is the insulating block having the binding screws Z Z towhich the wires are connected,said clamps also being connected to thecontact springs with which the bulb is brought into contact when held inthe bulb holder. The branch fitting 19 has extending out from one sidethereof the tube 1', which tube contains both contact pieces .9 s whichare separated by the insulating strip 7 extending longitudinally of thetube. When such tube is inserted through the opening k in the side ofthe shell of the bulb holder, its contact pieces 3 s will be broughtinto contact with the clamps Z Z, and the current is thus conducted intothe branch fitting, the contact pieces s s being connected to suitablebinding screws t t to which the wires are connected.

Further illustration of the device is not considered necessary, as theprinciple of this construction is above clearly set forth.

When in use, as the branch fitting is removable from the bulb holder,the user can simply insert its contact points into the opening oropenings in the side of-the bulb holder, so that they are brought intoelectrical connection with the positively and negatively chargedsurfaces, and the current will pass through the contact points into thebranch fitting and thence by the wire cords to the lamp, or motoroperating the fan, or like device. This will not in any way interferewith the use of the lamp in the main bulb holder, as by turning the keythe said lamp can be lighted and used independently of connection to thedrop-light, fan, or other like device. When it is not desired to use theside withdraw the branch fitting or plug from the bulb holder, when thecircuit to the droplight, fan, &c., is immediately broken. For thepurpose of covering the openings in the sides of the bulb holder, asuitable collar to may be employed, which can be slipped around the bodyof the bulb holder so as to expose theopening or openings therein, andwhen the branch fitting is removed from the bulb holder, such collar canhe slipped over the opening or openings.

What I claim as my invention, and desire to secureby Letters Patent, is-

1. The combination with a bulb holder for an incandescentlamp havingterminals therein adapted to connect with the supply wires, and a loopcontaining a switch and leading from said terminals to the lamp, of aremovable branch fitting or plug having contact points and adapted toenter through the side of the bulb holder and contact with the terpiecescontaining spring contact points adapted to engage with the springcontact pieces of the bulb holder, substantially as and for the purposesset forth.

3. The combination with a bulb holder for an incandescent lamp, havingcharged sur- 15 faces therein, and having one or more openings in theside of the case thereof, of a branch fitting or plug havingcontactpoints adapted to enter said openings, a movable collar on said bulbholder adapted by its movement to 20 cover or uncover said openings,substantially as set forth.

In testimony whereof I, the said THOMAS L. PFARR, Jr., have hereunto setmy hand.

THOMAS L. PFARR, JR. Witnesses:

RoB'r. D. TOTTEN, J. N. OooKE.

